The invention relates generally to mattresses having two horizontally coextensive chambers for air and water and more particularly to an air and water mattress and inflation apparatus which facilitates entry, repositioning and egress from the mattress.
Flotation sleep products have advanced from their beginnings wherein a relatively unstable elastomeric bladder was filled with water to support a person with varying degrees of comfort. Nearly every aspect of this product has been improved in the last three decades. The use of leak-proof, long life materials, improved seals, weight reduction and oscillation damping are the more significant areas of improvement.
One of the inherent benefits of water filled recumbent supports is the relatively low and uniform pressure applied to the tissue of a human body when supported thereby. Such relatively low and uniform pressure interferes only negligibly with surface adjacent circulation in the skin and body tissue. By contrast, circulation is diminished or temporarily curtailed due to the compression of blood vessels and tissue with conventional mattresses. Such improved circulation greatly reduces the incidence of decubitus ulcers and generally improves the circulation of bedridden patients.
The improved circulation of patients and the reduced incidence of decubitus ulcers is not without certain drawbacks. Perhaps the most significant is the difficulty attendant entry and egress from such a water mattress. Those familiar with water mattresses will attest to the difficulties encountered in rising to ones feet from a water mattress of conventional design. This is a particularly significant problem with infirm patients requiring hospital care. This general difficulty is coupled with a complication. Generally speaking, hospital beds position a patient several inches above the surface of a conventional, residential bed for numerous reasons relating to medical treatment, hygiene and patient comfort. Entry and egress from such a raised surface water mattress can present a nearly insurmountable problem for many patients. The alternative, of course, is to require assistance to enter or exit the water mattress which represents one additional responsibility for typically overworked nursing and orderly staffs.
Attempts have been made to solve this difficulty. For example, U.S. Pat. No. 3,456,270 discloses a flotation apparatus wherein a contoured support contains a water filled mattress and an adjustably filled air bladder positioned thereover. The air bladder includes transversely oriented chambers having equal cross sections. The air bladder extends from the head of the patient along the torso but does not support the lower legs.
U.S. Pat. No. 3,803,647 teaches a similar device. In the flotation bed disclosed in this patent, water is replaced by a fluid having a specific gravity substantially greater than one and preferably about two. This device also includes an inflatable bladder which may either be disposed below the fluid to raise the level of the supporting fluid when inflated or on top of the fluid to function as the support for the patient. In the latter configuration, the air chamber comprises a plurality of longitudinally oriented chambers. Air pressure is provided from an external air pump.
It is apparent from the foregoing that improvements in the art of water mattresses and particularly those including coextensive superposed air chambers for patient use are both possible and desirable.